The present invention relates to ribbon cartridges containing an endless print ribbon for use in printers and drive systems for the ribbon cartridges forming part of the printer. Particularly, the invention relates to a ribbon cartridge having component parts for transporting, guiding and storing the endless print ribbon and which parts are cooperable with a drive system mounted on the printer for driving the print ribbon, whereby the number of parts and, hence, the cost of the consumable ribbon cartridges are reduced.
In most commercial high-speed printers, ribbon cartridges are consumable items discarded with use and replaced with fresh cartridges. Even in those ribbon cartridges containing a re-inker and which cartridges therefore have extended useful life, ultimately the cartridge is discarded and replaced. Such ribbon cartridges typically mount the ribbon drive system within the cartridge and which drive system is therefore discarded with the ribbon cartridge. These ribbon drive systems substantially increase the cost of the ribbon cartridge. Consequently, otherwise reusable drive system components are discarded and replaced with new cartridges likewise containing duplicate and otherwise reusable drive system components.
In certain printing systems these disadvantages have been obviated to some extent by locating the drive rollers forming an integral part of the drive system in the printer. In this manner, the print ribbon cartridges do not carry the drive rollers and the same drive rollers of the printer are used to drive the ribbons of the replacement cartridges. A system of this type is disclosed in U.S. Pat. No. 4,293,234, issued Oct. 6, 1981. Such system apparently, however, has not resulted in any widespread use and presumably this is a result of a number of factors, including complexity of the system and its cost.
According to the present invention, there is provided a novel and improved ribbon cartridge and drive system therefor which locates the drive system for the print ribbon of the cartridge in the printer eliminating any necessity for the cartridge to carry and mount drive system components as integral parts thereof whereby substantial reductions in the cost of the consumable cartridges by elimination of the drive system components therefrom are achieved. To accomplish this, the present invention provides a replaceable ribbon cartridge in the form of an elongated, generally rectilinear housing having ribbon entrance and exit arms projecting to one side of the housing at its opposite ends, respectively. The housing includes top, bottom and side walls which in part define a ribbon storage chamber which extends over a substantial majority of the length of the housing. The endless ribbon thus extends from the ribbon storage chamber, preferably through a mobius loop, and along the exit arm, passes out of the exit arm for spanning between the tips of the exit and entrance arms, and reenters the cartridge through the entrance arm for return to the storage chamber. The bottom wall of the cartridge has an opening which, when the cartridge is applied in overlying relation to the printer deck, receives the ribbon drive system which is mounted on the printer deck. The print ribbon of the cartridge spans across the opening in the bottom wall of the cartridge and the drive system, as described hereinafter, has a mechanism for engaging and disengaging the print ribbon enabling the cartridge to be placed on the printer for use and removed therefrom for replacement. The cartridge therefore serves to transport, guide and store the ribbon but does not contain a drive system for the ribbon.
The cartridge, however, contains a stripper which performs the twofold function of providing a wall at one end of the ribbon storage chamber for maintaining the ribbon in a folded, preferably random folded, condition, as well as providing stripper elements for stripping the ribbon from the rollers forming part of the printer-mounted drive system for the ribbon when the cartridge is loaded into the printer for use. The stripper is mounted for generally linear movement within the cartridge housing between a retracted position and a position locating the stripper elements adjacent the nip of the drive system rollers to strip the ribbon from the rollers and feed it into the storage chamber. The cartridge is therefore specifically formed to transport, guide and store the ribbon and to cooperate with a drive system forming part of the printer which serves to engage and drive the ribbon when the cartridge is loaded into the printer and to release the ribbon when the cartridge is removed from the printer for replacement.
The ribbon cartridge hereof may or may not include a re-inker, depending upon the needs of the user of the cartridge and associated printer. Additionally, the cartridge is provided with a spooler for taking up slack in the ribbon spanning between the ends of the exit and entrance arms, thereby ensuring that the ribbon extending across the print mechanism, upon loading the cartridge into the printer, is straight and taut. It also simultaneously takes up slack in the ribbon spanning across the bottom opening in the cartridge to ensure, when the cartridge is loaded into the printer, that the ribbon will be engaged with the drive system. The spooler includes two parallel bars or pins carried by a manually rotatable device. By threading the ribbon between the bars or pins and rotating the device, the ribbon rapidly rolls up on the bars, tightening the ribbon spanning between the tips of the entrance and exit arms and across the cartridge opening. The freely rotatable spooler also enables the ribbon to be unwrapped therefrom when the drive system is engaged and printing commences.
It will be appreciated that the component parts of the ribbon cartridge described above may be provided in kit form for subsequent assembly. Thus, the housing may be provided in the form of discrete top and bottom wall parts, with the side walls being carried by one or the other of those parts or, alternatively, portions of the side walls may form parts of the top and bottom wall parts, respectively. The ribbon entrance and exit arms also form portions of the top and bottom wall component parts. The top and bottom walls are configured to define the storage chamber for the ribbon upon assembly thereof and the bottom wall part has an opening for receiving the roller drive mechanism upon assembly of the cartridge and loading it into the printer. The top and bottom wall parts may be assembled and secured one to the other to form the ribbon cartridge by staking, ultrasonic welding of the plastic material or otherwise, as desired.
As part of the kit, there is provided a stripper which includes a pair of laterally spaced stripper elements defining a slot therebetween for receiving the ribbon when the assembled cartridge is loaded onto the printer. The stripper also has a pair of depending pins which are receivable through openings, preferably elongated slots, in the bottom wall part such that, when the stripper is assembled into the cartridge, the pins project through the slots for engagement by a drive mechanism whereby the stripper may be moved longitudinally within and along the cartridge upon assembly. Guide surfaces are provided on the stripper to facilitate this movement. Various other parts may be formed as integral or attachable elements to the top and bottom wall parts. For example, pins for mounting guide rollers for the ribbon may project from one or the other of the top or bottom wall parts. The spooler may be provided as a separable part for alignment with openings in both the top and bottom wall parts upon assembly such that the spooler can be manually rotated.
In accordance with the present invention, the drive system is mounted on the printer deck and includes a control means for controllably displacing an idler roller toward and away from a drive roller between positions engaging the ribbon between the rollers and disengaging it from the rollers. The control means also linearly displaces a stripper actuating member engageable with the stripper in the cartridge upon loading the cartridge into the printer to move the stripper between its retracted and stripping positions. To accomplish the foregoing, the drive system includes a base secured to the printer deck and mounting a drive roller connected to a drive motor within the printer. A lever is movably mounted on the base, preferably pivotally mounted, and carries an idler roller for movement toward and away from the drive roller. A spring biases the lever for movement in a direction tending to engage the idler roller against the drive roller. The lever also pivotally carries an underlying cam. The cam is rotatable by a crank arm and is cooperable with a pin mounted on the base for displacing the lever against the bias of the spring in a direction moving the idler roller away from the drive roller. The cam carries a detent surface which cooperates with the pin for detenting the lever in a retracted position spacing the idler roller from the drive roller to enable placement of the print ribbon between the spaced rollers when the cartridge is loaded into the printer. By rotating the crank arm and moving the detent surface of the pin, the spring bias moves the lever into an engaged position, enabling the ribbon to be gripped between the idler and drive rollers.
Additionally, a stripper actuating member is slidably mounted on the printer deck and a stripper actuating member drive arm interconnects the cam and the stripper actuating arm. In a preferred form of the present invention, the actuating member has recesses for receiving pins which project downwardly from the stripper through elongated slots in the bottom wall of the cartridge such that the actuating member and stripper are engaged one with the other when the cartridge is loaded into the printer. The drive arm is connected to the cam such that, when the lever is in its retracted position spacing the idler roller from the drive roller, the actuating member is spaced and retracted from the rollers. It will be appreciated that this retracted position of the actuating member corresponds to the retracted position of the stripper in the cartridge.
To load the cartridge into the printer, and assuming the lever is detented to space the idler roller from the drive roller, the cartridge is placed on the printer deck with the drive system of the printer being received into the confines of the cartridge housing through the opening in the bottom wall, the crank handle also being received through an opening through the top wall of the cartridge. The print ribbon is thus disposed between the spaced idler and drive rollers. The stripper and stripper actuating member are also engaged one with the other and lie in their retracted positions. The crank arm is then rotated to release the detenting cam and pin, enabling the spring to rotate the lever to engage the ribbon between the idler and drive rollers. Simultaneously, rotation of the crank arm also rotates the cam to pull the drive arm and, hence, the actuating member in a direction toward the rollers. This, in turn, moves the stripper in the cartridge toward its operable position engaging the stripper elements in grooves on the idler and drive rollers. When engaged and the printer is operated, these stripper elements serve to strip the ribbon from the rollers and guide the ribbon into the storage chamber. The engagement of the stripper elements within grooves in the rollers also locks the cartridge against displacement from the printer deck. Additionally, the crank arm, when rotated to engage the ribbon between the rollers, is rotated into a position overlying the top wall of the cartridge housing and this also precludes removal of the cartridge from the printer deck.
To replace the cartridge after use, the crank arm is rotated so that the cam bears against the pin and rotates the lever against the spring bias to retract the idler roller from engagement with the ribbon and the drive roller. Simultaneously, the cam pushes the drive arm to move the actuating member away from the rollers and, consequently, the stripper in the cartridge is likewise moved away from the rollers. This withdraws the stripper elements from within the grooves of the idler and drive rollers, and aligns the crank arm with the openings through the top and bottom walls of the cartridge housing, enabling the cartridge to be moved from the printer deck.
In a preferred embodiment according to the present invention, there is provided a ribbon cartridge for a printer having a ribbon drive mechanism including a pair of rollers for engaging a print ribbon therebetween, comprising an elongated cartridge housing having top, bottom, and side walls and a pair of arms projecting to one side of the housing adjacent to opposite ends, the walls in part defining a storage chamber for receiving and storing the print ribbon, and the arms defining entrance and exit paths, respectively, for receiving the ribbon for delivery to the storage chamber and supplying the ribbon from the storage chamber for spanning between the arms. The bottom wall has an opening for receiving the pair of rollers substantially within the confines of the cartridge housing when the cartridge is loaded into the printer. A stripper having stripper elements is carried by the cartridge housing for movement between a first retracted position and a second extended position with the stripper elements disposed adjacent the pair of rollers for stripping the ribbon from the rollers. The bottom wall of the housing includes a pair of openings having an extent in the direction of the housing substantially at least equal to the range of movement of the stripper in the cartridge between the first and second positions. The stripper includes a pair of pins projecting through the openings below the bottom wall for engagement of at least one pin thereof by a drive carried by the printer for displacing the stripper from one of the first and second positions into the other of the first and second positions.
In a further preferred embodiment according to the present invention, there is provided a printer having a printer deck for mounting a printer cartridge containing print ribbon, a drive mechanism for the print ribbon, comprising drive and idler rollers carried by the printer and projecting from the printer deck. A lever carries the idler roller and is mounted for movement on the printer deck for moving the idler roller laterally toward and away from the drive roller. Means for moving the lever between a first position for engaging the print ribbon between the rollers and a second position spacing the idler roller from the drive roller, together with means for biasing the lever for movement into one of the first and second positions are provided. Means for detenting the lever in the other of said first and second positions, as well as control means for displacing the lever from the detented position enabling the lever for movement toward the one position are also provided. A ribbon stripper actuating member engages the ribbon stripper in the cartridge and is carried by the printer deck for movement toward and away from the rollers. An arm interconnects the member and the moving means such that the member is movable toward and away from the rollers in response to movement of the idler gear toward and away from the drive roller, respectively.
In a further preferred embodiment of the present invention, there is provided a parts kit for assembly into a ribbon cartridge for a printer having a ribbon drive mechanism, including a pair of rollers for engaging a ribbon therebetween, comprising a top wall part having portions for defining in part a storage chamber for a ribbon and a bottom wall part having portions for defining in part the storage chamber for the ribbon, the bottom wall part having an opening for receiving the ribbon drive mechanism upon loading the assembled cartridge into the printer. One of the top and bottom wall parts includes portions defining at least in part ribbon entrance and ribbon exit arms, the top and bottom wall parts being adapted for assembly one with the other to form the ribbon cartridge with the portions of the top and bottom wall parts defining a storage chamber for the ribbon. A stripper is provided for assembly within the cartridge, the stripper including a pair of laterally spaced stripper elements for stripping ribbon from the rollers and defining a slot therebetween for receiving ribbon upon assembly of the kit to form the cartridge and loading thereof into the printer, the stripper having guides for mounting the stripper within the cartridge upon its assembly for movement in a direction toward and away from the bottom opening and having at least one pin projecting therefrom and through the bottom wall part for engagement by the drive mechanism upon loading the assembled cartridge into the printer.
In a further preferred embodiment according to the present invention, there is provided a stripper for location in a ribbon cartridge for stripping ribbon from drive rollers and guiding the ribbon into a storage chamber of the cartridge, comprising a stripper body for generally horizontal slidable movement within the cartridge toward and away from the drive rollers and having a laterally extending wall and a pair of laterally spaced stripper elements projecting forwardly from the stripper body and defining a forwardly extending slot for receiving ribbon therebetween. Upstanding wall portions project from the laterally extending wall and are located rearwardly of the stripper elements for engaging ribbon in the storage chamber of the cartridge on the side of the stripper body opposite the stripper elements, the wall portions having an opening therebetween for receiving ribbon from the slot for entry into the storage chamber. A pair of pins project downwardly from the laterally extending wall adjacent its opposite ends and for termination below the stripper elements.
Accordingly, it is a primary object of the present invention to provide a novel and improved reduced cost print ribbon cartridge having a minimum of parts and functions, a kit of parts therefor and a drive system for the print ribbon carried by the printer for releasable engagement with the ribbon carried by the cartridge.
These and further objects and advantages of the present invention will become more apparent upon reference to the following specification, appended claims and drawings.